Seal means for valve assembly

ABSTRACT

An indexing valve assembly utilizes a mandrel having elastomeric seal means retained by a seal housing containing a seal island over which is slidably located a slotted indexing sleeve.

CROSS-REFERENCES TO RELATED APPLICATIONS.

This application is a continuation-in-part of an earlier applicationSer. No. 548,065 filed Feb. 7, 1975, now U.S. Pat. No. 4,022,427, byNorman Weldon Read, entitled "SLEEVE VALVE MANDREL AND SEAL MEANS FORINDEXING VALVE ASSEMBLY" , which earlier application is acontinuation-in-part of an original application Ser. No. 494,424, nowfiled Aug. 5, 1974 by Norman Weldon Read, entitled "SLEEVE VALVE MANDRELAND SEAL MEANS FOR INDEXING VALVE ASSEMBLY" . The above mentionedapplications are also related to a prior application by Norman WeldonRead entitled "INDEX EQUALIZING VALVE FOR RETRIEVABLE WELL PACKER" ,U.S. Pat. No. 3,815,676; which patent is hereby incorporated byreference into this application.

BACKGROUND OF THE INVENTION

This application involves improvements over certain features of theabove mentioned patent and patent applications. Specifically thisinvention provides an improved valve assembly to replace that disclosedin FIGS. 6 and 7 of the incorporated Read patent. Cited portions of theRead patent disclose a valve sleeve having a mandrel with externalgudgeon pins and a pair of ports spaced 180° apart around the valve.

An elastomeric seal sleeve is located on the inside surface of the valvesleeve. Although the valve assembly of the Read patent is a significantimprovement over the existing art and performs well, it was desirable toobtain a valve assembly having seals with great sealing ability but withreduced resistance to rotation.

This invention provides such a valve assembly by utilizing elastomericloop seals, which are retained on the seal mandrel by an internal islandand by a seal housing slidable onto the seal mandrel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded isometric assembly view of the valve assemblyshowing the relationship of the parts;

FIG. 2A is a side section view of the outer sleeve housing;

FIG. 2B is a top view of the housing of FIG. 2A;

FIG. 3A is a side section view of the inner sleeve housing;

FIG. 3B is a bottom view of the housing of FIG. 3A;

FIG. 3C is a side view of the housing rotated 90° from that of FIG. 3A;

FIG. 4A is an outside front view of one insert seal;

FIG. 4B is an inside front view of an insert seal;

FIG. 4C is a side cross-sectional view of an insert seal taken at linec--c of FIG. 4B;

FIG. 4D is an axial cross-sectional view of a seal taken at line d--d ofFIG. 4C;

FIG. 5 is a lateral side view of a vertical cross-section of the housingbody of an alternate embodiment;

FIG. 6 is an isometric exploded view of an alternate valving assembly;

FIGS. 7A and 7B comprise a partial cross-sectional view of the valvemechanism of FIG. 6 in its assembled form;

FIG. 8A is an axial cross-sectional view of the assembly of FIG. 7Ataken at section line a--a therein;

FIG. 8B is a partial cross-section view of the portion of FIG. 7Aencircled in dashed line b--b, rotated 90° from the orientation of FIG.7A;

FIG. 9 is a cross-sectional view of the valve mandrel;

FIG. 9A is an axial cross-sectional view of the mandrel of FIG. 9 takenat line a--a;

FIG. 9B is an axial cross-sectional view of FIG. 9 taken at line b--b;

FIG. 10 is a cross-sectional view of the valve sleeve;

FIG. 10A is an axial cross-sectional view taken at line a--a of FIG. 10;

FIG. 11 is a top view of the valve retention island;

FIG. 11A is an end cross-sectional view taken at line a--a of FIG. 11;

FIG. 11B is a side cross-sectional view taken at line b--b of FIG. 11A;

FIG. 12 is a side view of the seal housing;

FIG. 12A is a cross-sectional longitudinal view of the housing of FIG.12 taken at line a--a;

FIG. 12B is an axial cross-sectional view of the housing taken at lineb--b of FIG. 12; and,

FIG. 13 is a cross-sectional side view of an elastomeric loop seal foruse in the valve assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The valve sleeve assembly 110 is illustrated in an exploded assemblyview in FIG. 1 and comprises an outer seal housing 111, an inner sleeveseal retainer housing 112, and seal inserts 113a and 113b.

Referring to FIGS. 1, 2A and 2B, the outer housing 111 is illustrated ashaving a generally cylindrical tubular body 114 having two ports 115through the wall thereof and spaced 180° apart and two gudgeon pins 116extending radially outward from the body, 180° apart and 90° from theports 115.

At the top of housing 111 are spaced locking lugs 117 extending upwardlyand formed from the wall of body 114 by machining away spaces 118 fromthe wall. An inner annular stepped flange 119 extends radially inwardfrom the lower end of the wall of body 114. The flange has step 120 andbevelled shoulders 121 and 122.

FIGS. 1 and 3A through 3C illustrate the inner housing and seal carriersleeve 112 having a generally cylindrical tubular body section 124 withtwo ports 125 through the wall thereof, spaced 180° apart. Tworectangular seal windows 126 are formed through the wall of body section124, spaced 180° apart, and rotated 90° from ports 125. FIG. 3Cillustrates a full view of one of the windows 126, while FIG. 3A shows aside cross-sectional view through the centerline of the windows.

A raised annular shoulder portion 127 is formed externally on one end ofsleeve 112 and contains machined slots 128 extending partiallytherethrough, matching and complementing the upward extending lockinglugs 117 on housing 111.

Rectangular arcuate seal inserts 113a and 113b are illustrated in FIGS.4A through 4D. FIG. 4A shows an outside plan view of the inserts andillustrates an elastomeric seal channel 130 ovally encircling a centralport 131 passing through the insert. A similar oval seal channel 132 isformed on the inside of the inserts as illustrated in the inside planview 4B. A cross-sectional side view of the insert in FIG. 4C and thecross-sectional axial end view of FIG. 4D show the relationship of theseal groove channels in the insert leaf. Broad, flat oval seal member134 is cemented or bonded in channel 132 as illustrated in FIG. 4C. Seal133, located in channel 130, may also be cemented or bonded in place ifdesirable, but this is not required.

When assembled in the indexing valve of the aforementioned Read patent,the valving assembly herein disclosed functions as an integral unit. Therectangular seal inserts 113a and 113b are located, in relativelysnug-fitting relationship, in the windows 126 of inner sleeve 112.Sleeve 112 is relatively closely fitted within housing 111 with lugs 117engaged in locking relationship in matching spaces 128. The inner sleeve112 and outer housing 111 are maintained in locked relationship byabutment above and below with other portions of the indexing valvemechanism.

The inner seal 134 contacts portion 54 of mandrel 14 of the indexingvalve assembly as illustrated in the incorporated Read patent. The outerseal is in constant sealing contact with the inner wall of the outerhousing 111.

During the operation of the indexing valve assembly, the ports 59 ofmandrel 14 as shown in the Read patent, FIG. 4, are aligned with ports115 of this valving apparatus 110 and flow through the valve isachieved. When the indexing valve is manipulated to close ports 59,assembly 110 is rotated or "indexed" 90° to place the seal inserts 113aand 113b over ports 59. Seal grooves 132 are made in a large enough ovalto completely surround port area 59 and provide sealing capabilitybetween ports 59 and the interior of the inserts 113. Since ports 131through the inserts allow pressure to pass therethrough, the oval seals133 provide sealing between the inserts and the inner wall of housing111.

Seals 133 may be left out of the assembly by plugging ports 131 but nopressure balancing is achieved and the pressure force outward or inwardon the seal inserts 113 is determined by the entire area of the insertlocated within seal 134.

In the embodiment shown in FIGS. 4A through 4D, a partial pressurebalancing of the seal insert is achieved by transferring pressurethrough ports 131 to the low pressure side of the insert. The force dueto pressure differential is determined by the difference in areasenclosed by seals 133 and the areas enclosed by seals 134.

A complete pressure balance may be achieved by making the enclosed areaswithin seals 133 equal to the enclosed areas within seals 134. Thiswould mean that portions of the seal grooves 130 and 132 would lieradially in line with each other which would require a much thickerinsert to prevent intersection of the two grooves and cutting through ofthe entire thickness of the insert. This thicker insert may be desirablein instances where the tool inner diameter is not critical and highdifferential pressures make pressure-balancing necessary. In the presentembodiment, one seal groove was made in a smaller oval to fall inside ofthe radial projection of the other groove and prevent cutting through ofthe relatively thin insert leaf. This relationship of the seal groovesis clear from studying FIG. 4D. The pressure imbalance from thedifference in diameters of the oval seals 133 and 134 is relativelysmall and is not sufficient to cause high rotational friction betweenassembly 110 and mandrel 59 of the patented mechanism nor will it causeundesirable extrusion of the elastomeric seal out of its channel.

FIG. 5 illustrates a lateral side view in vertical cross-section of thehousing body of an alternate embodiment. In this embodiment, the outerhousing 111 and seal retainer housing 112 of FIG. 1 have been formed asa single tubular body member 211.

Body 211 is a tubular member adapted for sliding telescopic engagementover a ported mandrel such as that illustrated in FIGS. 1A and 1B of theabove mentioned Read patent. Body 211 has a pair of opposed ports 215passing laterally through the wall thereof. A pair of arcuate sealinsert recesses 226 are formed in the inner wall of body 211 spacedopposite from each other and angularly displaced from ports 215. A pairof gudgeon pins 216 extend radially outward from body 211 at 180°spacing from each other and spaced approximately 90° from ports 215.

Recesses 226 are arranged to receive in relatively close-fittingrelationship the seal inserts 133a and 133b as illustrated in FIGS. 4Athrough 4D.

Operation of the assembly is analogous to operation of the firstembodiment with the housing 211 operating as would the locked assemblyof housings 111 and 112.

The advantages of the present invention include the greatly reducedrotational friction between the valve assembly 110 and the mandrel uponwhich it rotates. This is because the actual contact area of theelastomeric seals 113 is only a small fraction of the area of theelastomeric seal covering the entire inner bore of the patentedmechanism.

This rotational friction is even further reduced by making the sealinsert partially or wholly pressure balanced thereby reducing the forceholding the seal against the mandrel. Furthermore, the use of thefloating type insert seal provides a more flexible and efficient sealagainst the inner mandrel with just the minimum use of elastomericmaterial.

Also, the strength of the seal is maximized by having metal support bothon the inside edge and the outside edge of each seal. This is providedby the channel in the seal insert which retains the seal and providesthe two-way lateral support as well as the radial support. This is animprovement over the large sheath type seal used previously whichallowed pressure extrusion and bubbling of the sheath type seal arisingfrom gas penetration through the large seal area.

Referring now to FIGS. 6 through 13, an alternate embodiment of thepresent invention is disclosed utilizing a loop type seal means whereinimproved seal retention means is utilized.

In FIG. 6 an exploded isometric view of the valve assembly is shownutilizing a valve mandrel 301, a valve sleeve 302, and a valve housing303. A loop seal 304 is retained within sleeve 302 by an oval sealretention island 305 secured to mandrel 301 by threaded means such asscrews 306.

In FIGS. 7A, 7B, 8A, and 8B, the valve assembly of FIG. 6 is shownincorporated into an indexing valve mechanism 310. The indexing valvemechanism 310 is particularly suitable for use with multiple packers andprovides an equalizing valving function for equalizing pressures acrossone or more packers. The valving mechanism 310 comprises a housing 311attached to the threaded top connection 312 and, at its lower end,having attached thereto a J-slot housing 313 with a J-slot 314 formed onthe inner wall thereof.

A J-slot mandrel 315 is located slidably within housing 313 and utilizesa pair of 180°-oriented external lugs 316 slidably engaged in J-slots314 which are formed 180° apart in the inner wall of J-slot housing 313.The valving mandrel 301 is slidably located within an indexing sleeve307 which in turn is located within housing 311. Mandrel 310 has anindexing pin 308 passing transversly through the upper end thereof heldin place by threaded cap screw 309. Pin 308 extends outwardly frommandrel 301 and engages at each end in indexing slots 320 formed inindexing sleeve 307.

Valve mandrel 301 has at its lower end a reduced section 317 which ispartially counterbore to form a flow bore 318 extending to the lower endof section 317. Valve sleeve 302 is located concentrically on section317, and valve housing 303 is slidably and concentrically located onsleeve 302.

FIG. 8A is an axial cross-section view taken at line a--a in FIG. 7Afurther showing the relationships among the valve mechanism elementsincluding mandrel section 317, sleeve 302, housing 303, indexing sleeve307 and valve housing 311.

FIG. 8B is a lateral partial cross-sectional view of the valving sectionof mechanism 310 rotated 90° from the FIG. 7A orientation in order toshow the porting and sealing elements.

It should be noted that as disclosed in FIG. 8A, the mechanism asillustrated in FIGS. 7A and 8B is symmetric about the longitudinalcenter line and a complete cross-sectional view would indicate a mirrorimage of the partial cross-section of FIG. 8B, repeated in identicalfashion at 180° therefrom. Operation of the valving mechanism 310 isbasically identical to the operation of the mechanism as disclosed inthe above incorporated Read patent, U.S. Pat. No. 3,815,676.

FIG. 9 is a cross-sectional view of the valve mandrel 301. The mandrelcomprises a generally solid upper section 319 having a transverselateral bore 321 passing therethrough and adapted to receive an indexingpin 308, as shown in FIG. 7A. A counterbore 322 intersecting bore 321 isprovided and has a threaded section 322a and a countersunk portion 322b.Bore 322 is adapted to intersect passage 321 and receive a retention capscrew 309 for securing pin 308 in bore 321.

Mandrel 301 has at its lower half a reduced section 317 which issubstantially hollow and contains a generally central bore passage 318therein. A pair of diametrically opposed flow ports 323 are formedthrough the wall of section 317 communicating with bore passage 318.Threaded holes 324 are provided near ports 323 for securing the sealretention islands thereto.

A transverse pin bore 325 is provided through the upper end of thereduced section 317 of mandrel 301 and generally intersects the centralaxis of the mandrel at approximately 90°. Pin bore 325 is adapted toreceive an elongated pin 326 as shown in FIG. 6 which pin also passesthrough aligned holes in sleeve 302 and coacts with mandrel 301 andsleeve 302 to prevent relative movement therebetween.

FIG. 9A is an axial cross-sectional end view of the mandrel 301 taken atline a--a of FIG. 9 and illustrates the intersection of passages 321 and322.

FIG. 9B is an axial end view cross-section of lower section 317 lockingalong section line b--b and illustrating ports 323 and flow passage 318.

FIG. 10 is a lateral cross-sectional view taken through the centrallongitudinal axis of valve housing 303 indicating the indexing lugs 327formed on opposite sides of the housing. A flow area comprising aplurality of peripheral slit openings 328 is provided at each side ofhousing 303 between the lugs 327. A corresponding flow area is locatedopposite flow area 328, 180° around housing 303 as indicated in FIG. 9Aat 329.

FIGS. 11, 11A and 11B are close-up illustrations of the seal retentionisland 305 which provides retention means for the loop seal 304 in thevalving mechanism.

It should be noted that the seal structure described with respect toFIGS. 11 through 11B also applies at the opposite side of the mechanismapproximately 180° oriented from that illustrated. The opposite sealmechanism is substantially identical to that of FIG. 10 and thedescription with respect to FIG. 10 is likewise applicable to both sealstructures.

While it is not entirely necessary that a dual ported, dual sealingarrangement be utilized, for instance a single ported sealingarrangement can be used, it is preferable to use the dual porting systemparticularly as illustrated in FIG. 8A to obtain better flowdistribution and to simplify the indexing mechanism in the valvestructure.

In FIG. 11 the seal retention island 305 is illustrated as an elongatedoval plate having an arcute curvature substantially similar to thecurvature of valve sleeve 302. The plate 305 is sized to fit within asimilar oval opening formed in housing 302 leaving a relatively constantwidth channel therebetween. Island 305 has a centrally locatedconcentric flow port 330 passing therethrough and has a countersunkscrew opening 331 near each end thereof adapted to receive threadedfasteners for attaching the island 305 to mandrel section 317.

FIG. 12 illustrates the valve sleeve 302 having a pair of elongated ovalslots 332 formed in opposed position passing through the walls of thesleeve. Slots 332 are of sufficient size to allow concentric placementof islands 305 therein with a constant space running peripherallytherearound.

FIGS. 12A and 12B are cross-sectional illustrations of sleeve 302illustrating the orientation of slots 332 and further illustrating theretention pin openings 333 also passing through the wall of sleeve 302and adapted for receiving in relatively snug engagement the retentionpin 326.

FIG. 13 illustrates a cross-sectional view of one preferred embodimentfor the loop seal 304 to be utilized in the valving mechanism. Thecross-sectional configuration of the loop seal wall is basically arounded triangular section having a wide base 304a and an opposednarrowed peak 304b. A tightly coiled spring 334 is encased within theelastomeric material of seal 304.

Assembly of the valving mechanism is accomplished by sliding sleeve 302upon section 317 of mandrel 301 which preferably fits in a relativelyclose tolerance, slidable relationship within sleeve 302. The sleeve ismoved upward until it abuts the enlarged upper section 319 of mandrel301. Sleeve 302 is oriented so that slots 332 coincide with ports 323and openings 333 coincide with pin bore 325 in mandrel 301.

A relatively snug fitting retention pin 326 is then inserted throughopenings 333 and pin bore 325, thereby securing sleeve 302 againstmovement with respect to mandrel 301. Preferably the ends of pin 326 aresubstantially flush with the outer surface of sleeve 302. At this time,loop seals 304 are placed within slots 332 on each side of sleeve 302and then the retention island 305 are placed inside the loop seals andsecuredly fastened to section 317 by means of screws 306 engaged inopenings 324.

Valve housing 303 is then placed over sleeve 302 in relatively tightfitting slidable relationship thereon with slotted areas 328substantially coinciding with flow openings 330 in islands 305. Thecompleted valve subassembly is then inserted into the index equalizingvalve 310 and secured therein as indicated in FIGS. 7A and 7B, and theoperation of the indexing equalizing valve is substantially similar tothe operation described in the aforementioned Read patent.

Referring again to FIG. 8A, it can be seen how the tapered walls ofisland 305 and slots 332 in valve sleeve 302 provide a trapezoidalchannel area wider at the base than at the top, which acts as a dovetailchannel in retaining the loop seal member in sealing engagement withmandrel section 317.

Valving operation is achieved through the indexed rotational movement ofvalve housing 303 around valve sleeve 302, alternatly communicatingslotted flow areas 328 with flow ports 330 in plates 305. The slottedconstruction of flow areas 328 and 329 provides additional resistanceagainst extrusion of the loop seals from the peripheral space aroundplates 305. Closing of the valving system is accomplished by indexingthe valve housing 303 90° on sleeve 302 from the orientation of FIG. 7Asuch that the slotted areas 328 and 329 are no longer in communicationwith flow ports 330, and loop seals 304 are surrounding flow ports 330and sealingly engaging the inner wall of housing 303 to prevent fluidcommunication with bore 318.

Advantages of the present invention include the highly efficient sealingsystem comprising the loop seal, the seal sleeve and the seal island.The production of the sleeve and the island as separate components,which when combined form a highly effective seal retention channel, isvery economical in manufacture as opposed to the complex and expensivemethod of machining such grooves into the walls of cylindrical bodies.

Furthermore, because of the ease of assembly, the material which can beutilized for the loop seal can be selected from a large range ofavailable materials having a wide range of flexibility, hardness andother properties. This is true also because there is no requirement forbonding the seal to the metal and many elastomeric materials notsuitable for bonding to metal can now be utilized in the seal elements.

Furthermore, where the islands have been secured to the mandrel in thedescription above, it is clear that the islands could be left to floatfreely on the mandrel inside the loop seals without need for securingthem to the mandrel.

Although a specific preferred embodiment of the present invention hasbeen described in the detailed description above, the description is notintended to limit the invention to the particular forms of embodimentsdisclosed therein since they are to be recognized as illustrative ratherthan restrictive and it will be obvious to those skilled in the art thatthe invention is not so limited. For example, whereas elongated ovalseal retention means are illustrated, these could be of any suitableshape such as rectangular or circular. Also the cross-sectionalconfiguration of the loop seal body could be circular or any other shapein addition to the triangular configuration described. Furthermore, theloop seals can be made solely of a single elastomeric material or of acombination of different materials including fibers and metalreinforcing.

Locking means other than a transverse pin through the valve sleeve andmandrel could be utilized to lock the two elements together; forinstance coengaging teeth or lugs formed on the two elements could beutilized for such locking means. Threaded bolts could be used to lockthe sleeve on the mandrel as they do the island plate to the mandrel.Thus, the invention is declared to cover all changes and modificationsof the specific example of the invention herein disclosed for purposesof illustration which do not constitute departures from the spirit andscope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A seal assembly forproviding a sealing valve action between two concentric, ported, tubularmembers, said seal assembly comprising:a cylindrical seal carrier sleevearranged for a snug slidable fit concentrically between two tubularmembers; seal opening means passing through the wall of said carriersleeve and arranged to be placed in communication with ports in twotubular members; elastomeric loop seal means adapted for snug fittingengagement inside said seal opening means and for sealingly engaging twotubular members; and, retention island means comprising arcuate platemeans having similar surface curvature to that of said carrier sleeveand adapted for equi-spaced placement in said seal opening means inretaining abutment with said loop seal means.
 2. The seal assembly ofclaim 1 wherein said carrier sleeve opening means and said plate meanshave angled edges adapted to provide a dovetail seal space.
 3. The sealassembly of claim 1 further comprising attachment means for removablysecuring said plate means to an inner tubular member sleeve.
 4. The sealassembly of claim 1 wherein said loop seal comprises a closed loopo-ring seal of elastomeric material.
 5. The seal assembly of claim 1wherein said loop seal comprises a closed loop seal member having agenerally triangular cross-sectional configuration and furthercomprising tightly coiled reinforcement means contained within said sealmember.
 6. A low-torque, high efficiency sealing assembly for providingsealing engagement between two ported, concentric, tubular valvemembers, said sealing assembly comprising:a seal sleeve adapted forclose fitting engagement concentrically between two valve members; sealmember openings through the wall of said seal sleeve arranged to overlayports in two valve members and having curvilinear configuration withinwardly angled edges; elastomeric loop seals abuttingly held in saidopenings and sealingly engaging two valve members around the portstherein; seal retention plates having surface curvature similar to thatof said seal sleeve and curvilinear configuration smaller than butsimilar to that of said openings, and adapted to fit abuttingly in saidloop seals; said plates having an angled peripheral edge adapted to forma dovetail channel with said seal sleeve and the inner tubular member;and, flow ports through said plates and arranged for being placed incommunication with ports in two valve members.
 7. The sealing assemblyof claim 6 wherein said loop seals each comprise an elastomericclosed-loop seal having a generally triangular cross-sectionalconfiguration and further comprise flexible reinforcing means withinsaid seal made of a material of greater strength than said elastomericmaterial.